Precipitation during the 2016-2017 water year exceeded 100 inches across the higher elevations in the Sierra Nevada Mountains, with lesser amounts, 25-50 inches, falling across lower elevations.
The relatively large amount of precipitation helped to drastically increase the snowpack in the mountains and raise reservoir levels across the state. As of October 9, most of the reservoir levels across the state were higher than average, including Lake Shasta which was 73% full—23% higher than normal for this time of year.
Across the Northern Sierra Mountains, where the highest rainfall amounts were recorded, an eight-station average of precipitation totals during the 2016-2017 water year reached 94.7 inches, the highest on record and over six inches higher than the previous record set in 1982-83. Farther south near the agriculture-heavy San Joaquin Valley, a five-station average showed that the past water year was the second wettest on record after 72.7 inches fell.